The invention relates to a rollable roof ridge ventilation element for slanted roofs, consisting of a strip-type, air-permeable carrier material that is connected to edge strips of an elastically deformable plastic film. A roof ridge ventilation element of this type is already known from German patent document DE 198 21 035 B4.
Roof ridge ventilation elements are commercially available and are used for the air-permeable sealing of ridge and hip stones on building roofs. These ventilation elements consist of an air-permeable strip-type carrier material that is provided with self-adhesive tapes along its edges. The strip-type carrier material is installed longitudinally in the center of the ridge or hip pole and is attached with the aid of its self-adhesive tapes to the adjacent roof tiles. Since roof tiles for the most part do not have a flat surface, but a curved (pan-shaped) surface, the strip-type carrier material is either pleated across the total width, in the manner of a bellows, or only the edge regions that must be glued on are pleated or cut to form a fringe. Following this, the ridge or hip stones are fitted over the completely installed ventilation element and are held in place by means of brackets.
Commercially available roof ridge ventilation elements have different structural features to ensure a sufficient flow of air from the roof inside area through the strip-type carrier material and into the transverse channel, through which outside air flows and which is located between the ridge or hip stone and the top of the roofing mat. The simplest variant of a carrier material consists of a foam-material strip, having a thickness of approximately 13 mm and an air-permeability of up to 99 percent. The center region and the edge regions of the foam strip are thermally compressed to a thickness of approximately 1 mm, wherein the center region remains flat and the edge regions are profiled so as to be undulating. Owing to its extremely low weight and simultaneously large surface area, the known foam material roof ridge ventilation element is always in danger of being carried off by wind during the installation.
According to a second variant, the strip-type carrier material consists of an extremely thin and light-weight, needle-perforated plastic non-woven with low rigidity, which is provided along both edge regions with metal strips of aluminum foil, installed on the top, and is provided in the center region, on the underside, with a stiffer and thicker reinforcements strip of plastic non-woven material. Following the gluing on of the metal strip and the reinforcement strip, profile rollers are used to pleat the strip-type carrier material over its complete width. In addition, holes are punched into both superimposed non-woven materials in the center region during the profile rolling, wherein these holes are spaced apart in longitudinal direction of the strip by approximately half the pitch height for the pleating.
A third variant for a roof ridge ventilation element, disclosed in German patent document DE 196 04 256 A1, is based on the idea that a strip of perforated synthetic or rubber is best suited for an air-permeable sealing. The high density and thus the high specific weight of a rubber strip provides excellent preconditions for installing such a strip-type material on the roof, even if strong winds are present, without the danger of the wind carrying off the ventilation element. However, the difficulty with using a rubber strip is that it cannot be pleated permanently by means of profile rolling because of its elastic properties, but always has a tendency to return to its smooth, flat shape. To counter this problem and permanently pleat a strip of rubber, first the edge regions and then the center region of the smooth, flat strip of rubber for a known roof ridge ventilation element are covered with a thin metal strip, for example an aluminum foil, which can be deformed permanently with little force expenditure. Following this, only the metal strips and the thereto adhering regions of the rubber strip are pleated with the aid of profile rollers. The strength of the metal strips is selected such that the elastic forces of the pleated strip of rubber are not sufficient to restore the pleated metal strips to the original shape, meaning to smooth them out again.
German patent document DE 198 21 035 discloses a different rollable roof ridge ventilation element, for which the edge strips are embodied of a self-adhesive, elastically deformable rubber material and are glued onto the strip-type carrier material that is positioned in-between. The edge strips are covered on the top with a thin layer of an elastically deformable plastic film, designed to protect the edge strips against destructive UV radiation.
However, it has been found that with all known, rollable roof ridge ventilation elements, drizzle or flying snow can enter the roof inside area by way of the ventilation element if wind conditions are unfavorable.